Sutle - Save and organize resources into a directed learning path.
Wikipedia - Wikipedia is a free online encyclopedia, created and edited by volunteers around the world and hosted by the Wikimedia Foundation.
Golden - Mapping all human knowledge
Kiwix - Kiwix enables you to have the whole Wikipedia at hand wherever you go!
QuestBook - The fastest way to teach and learn
Oppia - Oppia is a free, open-source learning platform.